Innovative Trend: Smart Waste Management Systems

Joe Flanagan

 

The past few years have been marked by tremendous technological trends such as electric vehicles, virtual reality, Internet of things (IoT), artificial intelligence, etc. These technologies have been applied to various industries that affect our daily lives.

However, in the area of waste management for smart cities, there are still a lot of untapped business potentials. To emphasize, according to CISCO—a network hardware company—the market potential of smart cities is forecasted to approach $14.4 billion by 2022 [1].  Also, it is predicted that about two-thirds of the global population will be living in cities by 2030.

Smart waste management systems (SWMS) involves the application of modern technological innovations to the disposal, collection and transportation of municipal wastes. SWMS are a part of the bid to create smart cities that run on the IoT. There have been some proposed designs and concepts, and there are also some companies that create working smart waste solutions. Also, based on some of the papers reviewed in the development of this article, the major players for this new innovative trend in waste management are from the U.S., UK, Europe and Asia.

This article briefly discusses actual designs used by key companies, the general architecture of SWMS, the benefits of SWMS, some gaps in the present design, and recommended designs for improvement.

A Look at Existing Solutions

The following companies and products are some of the presently implemented solutions:

1. Enevo: Launched in 2010, this company invested eight years of research and development to produce its advanced technology that consists of sensors, computer networking, and data analytics software—all for enhanced waste management services. According to [2], EnevoONE has been tested successfully in Nottingham, and it helped to reduce the daily waste collection by about 89 percent. Enevo’s solutions do not involve the provision of the whole smart bin, just the sensing parts, and the software. It uses an ultrasonic sonar tech that performs level sensing to estimate the amount of trash in the container. This sensor can be installed in a container and then start working to recognize different waste types; it is of two types – the WE-008 and the WEL-001. The sensors are equipped with a high-performance battery that can last for over 10 years. According to [2], the sensor measurements are transmitted to the company’s servers through a GSM module.
2. Sensoneo: An award-winning company created in 2014 that also provides SWMS solutions that were developed from years of R&D and testing. It provides its services to 137 locations across Europe, North and South America, Middle-East, Australia and New Zealand. Their service involves the use of an in-house manufactured ultrasonic sensor that integrates with highly advanced software.
3. SENSdumpster: This device is manufactured by SAYME, a company based in Spain that provides IoT solutions. The device consists of two ultrasonic sensors and a temperature sensor; in addition to being able to provide information about the level of waste, it also monitors the environmental temperature, such as in case of a fire outbreak. It has a replaceable battery capacity of about five years. The SENSdumpster is compatible with any type of waste and it uses LoRa, Sigfox, GPRS, and NB-IoT for its data communication networks.
4. The LV3000 and LV4000 Series: These are a line of capacitive load sensing products produced by Omega engineering [2]. These products are useful for monitoring special industrial wastes, especially in applications that deal with water, oil, corrosives, pastes, some solids, etc. The sensor’s capacitance changes as the waste products in the bin changes, hence providing an excellent indication of the trash level. The various designs available can be used with both conductive and non-conductive types of wastes.
5. Bigbelly:This Company was founded in 2003 and it is a world-leading smart waste and recycling system that deploys smart, solar-powered, sensor-equipped waste compacting and recycling stations. They are almost similar to the other services rendered by the companies mentioned earlier. However, their bins are solar-powered and have built-in compaction system. These extra features make its service costly—one station costs about $4000, with the addition of $500 for battery replacement, and $20 per year for maintenance [2].

Several other companies offer similar products and services; examples are ENVAC, Libellium, Sotkon, First Sensor, Evreka, NordSense, etc.

General Architecture of an SWMS
It can be seen that the various solutions have almost the same technique, with some difference being geographical locations, sensor types, waste types, communication protocols and mode of power supply. Generally, the architecture used by these innovative companies can be illustrated in the block diagram below.

In the diagram, the sensor unit includes:

• Level sensors like ultrasonic sensors, capacitive sensors, hydrostatic sensors;
• Temperature sensors, antitheft sensors, radio frequency identification tags, GPS location trackers, etc.
• Micro-processing units such as Arduino, Raspberry Pi, Buzzboards, MakeSpace, and other embedded systems hardware [1].

The sensor unit detects the level of waste, environmental temperature, location, etc. and then transmit its output to through a wireless sensor network (WSN). The WSN can be made up of wireless hardware modules like GSM, Wi-Fi, or Bluetooth; the network can operate on various wireless networking protocols like Zigbee, LoRA, etc.

The networks route the sensor data to the company’s server; the server then relays this data into a data analytics software that produces useful information about the waste level, and other environmental conditions. This information is then used for the process of waste management, providing a means of automating the traditional manual waste management process.

Furthermore, some also include a compactor system that responds to the level sensor output and then compacts the materials in the trash can, to provide more space, hence saving operating expenses.

The Benefits of SWMS
These include:

1. It would enable government authorities involved in SWMS to properly monitor the quality of service rendered by these smart waste solutions companies [3].
2. The information obtained will be used by local authorities to develop better environmental strategies that can improve the quality of life of its citizens [2].
3. The efficient management of waste can reduce the risk of disease outbreak in a city, thereby enabling a healthier environment.
4. The waste gathering companies by implement smart solutions can improve its services by using the information obtained for the optimization of waste collection through efficient route planning, reduce operation expenses, and provide transparent services to its customers.
5. For the service consumers, it will lessen the burden of manually monitoring the trash level, as they can receive accurate real-time status reports of the trash level on their smartphones.

Also, indirectly, smart waste collection route optimization can help reduce traffic in the city, as fewer waste trucks will be moving around; hence enabling city members’ easier access to workplaces.

Proposed Design for Improved Solutions
There are some suggestions for improvement of the present SWMS solutions; they are based on some gaps that still exist such as:

• In catering for non-uniform trash distribution inside the containers. For example, someone can mistakenly dump a huge empty carton inside the trash can and this can automatically appear to the level sensor as a full trash level.
• There are very few means of preventing overloading of the waste collection trucks or even for ensuring safe hoisting and hauling of the trash cans.
• There is also no means of ensuring that the right amount of trash collected is what is delivered to the dumpsite or recycling stations.

In light of these few gaps, a weight-based solution is proposed as follows:

1. The integration of weight sensors together with other level sensors—that is sensor fusion—can tackle the issue of non-uniform distribution discussed earlier. Together, they would provide a better amount and level estimation and then used to control a compactor that would compress the wastes. A load cell device is shown in the figure below. These load sensors can easily be installed under the smart bins; so existing SWMS companies can partner with load cell manufacturing companies like Tacuna Systems, Anyload, Vishay PG, etc. to develop customized products. This would leverage on the existing level of R&D that has gone into the products of each industry thereby reducing cost and enabling faster implementation.
2. The waste collection trucks can be equipped with smart hoisting and hauling structures that will be able to sense the weight of the trash bin they are lifting. This can prevent accidents caused by excessive weights.
3. Finally, the truck itself can be equipped with a means to monitor the amount of trash material collected by using a weight sensor. The weights of trash delivered and the weight of trash collected can then be compared for better decision making and transparent services.

Summary
In summary, this article has introduced the concept of using various technologies to provide smart waste management solutions, it mentioned some key companies, their solution techniques, and products, the various benefits of SWMS, and finally proposed an improvement to the existing solutions.

Joe Flanagan has more than 12 years in electronic engineering and design and is the current Project Engineer at Tacuna Systems. They provide hardware and service solutions for the for the strain measurement industry across a range of applications. For more information, visit www.tacunasystems.com.

Notes

1. Chin and V. Callaghan, “Recyclable, Eco-Friendly, On-Demand Bin (ReDBin),” 014 International Conference on Intelligent Environments, pp. 222-225, 2014.

2. Maurizio Giacobbe, Carlo Puliafito ,Marco Lucio Scarpa, “The Big Bucket: An IoT Cloud Solution for Smart Waste Management in Smart Cities,” in European Conference on Service-Oriented and Cloud Computing (ESOCC), Vienna, Austria, 2016.

3. M F Omar et al, “Implementation of spatial smart waste management system in Malaysia,” in IOP Conf. Ser.: Earth Environ. Sci., 2016.